i) Field of the Invention
The present invention relates to a disk recording/reproducing apparatus which is constituted to record a signal on a disk by a pickup and to reproduce a signal recorded on the disk.
ii) Description of Related Art
Optical disk players having an optical pickup for reading signals recorded on a disk have become common items, and in recent years optical disk recording/reproducing apparatuses having a constitution including, in addition to reproduction capability, a capability of recording a signal on a disk by emitting a light beam from a laser element incorporated in the optical pickup have also become commercially available.
A typical such optical disk recording/reproducing apparatus records the signal in response to a recording command from a computer apparatus as a host apparatus. Such recording operation includes storing the signal to be recorded on the disk once in a buffer RAM, reading out the signal stored in the buffer RAM, modulating the signal, and supplying the signal to the laser element to record the signal onto the disk.
When the signal is normally recorded onto the disk, a writing operation of recording signal output from a computer apparatus into the buffer RAM, reading operation of the signal from the buffer RAM, and recording operation of the read signal onto the disk are carried out in accordance with the size of the recording signal or the situation or state of recording on the disk itself.
During the signal recording operation, when the amount of recording signal data stored in the buffer RAM becomes insufficient, signal recording onto the disk cannot continue, that is, a so-called buffer underrun state results. As a method for solving the problem, there is a known technique including steps of halting the recording operation onto the disk when the amount of the recording signal data stored in the buffer RAM falls below a predetermined value, which is an interruption setting value; and the resuming the recording operation onto the disk when the amount of the recording signal stored in the buffer RAM again exceeds a predetermined value, a resumption setting value.
In this technique, a recording interruption and resuming operation is carried out. The recording resuming operation includes reproducing the signal recorded on the disk before interruption of the recording, and resuming the recording operation based on the reproduced signal.
With this technique, the recording operation onto the disk in the optical disk recording/reproducing apparatus is carried out at a constant linear speed. However, when the disk is rotated/driven at a constant linear speed, the rotation angular speed of the disk is higher on the inner peripheral side of the disk than along the outer periphery. Therefore, it is technically difficult to rotate/drive the disk at a high linear speed constant on the inner and outer peripheral sides of the disk.
As a method for solving the problem, a technique for raising the linear speed with displacement of a recording position to the outer peripheral side from the inner peripheral side of the disk has been developed.